A known surgical mesh for cranial applications is disclosed in U.S. Pat. No. 5,346,492. The known mesh includes a plurality of chamfered, square perforations, each for receiving a screw. The square configuration of the perforations makes the mesh more flexible than if the perforations were true circles. Clinical testing has shown that such a mesh having circular perforations is overly rigid and subject to cracking. By rounding the corners of generally square-shaped perforations, a mesh with sufficient flexibility and resistance to cracking is produced.
The square perforation design of the mesh in U.S. Pat. No. 5,346,492 has a drawback though. When a screw is received through a respective square perforation, only point contact is made between a head portion of the screw and each of the four surfaces defining the respective square perforation. Such point contact at four locations does not always provide sufficient attachment strength and may permit movement or shifting of the mesh. Consequently, a need exists for a mesh having perforations that provide for more than point contact with the bone screws, such as circular perforations, yet which retains adequate flexibility and resistance to cracking. Further, as with any cranial mesh, the mesh and bone screws should be as low profile (or thin in cross-section) as possible for aesthetic purposes.